import re
LEFT = '<'
RIGHT = '>'
CENTER = '^'
class FormatColumns:
'''Format some columns of text with constraints on the widths of the
columns and the alignment of the text inside the columns.
'''
def __init__(self, columns, contents, spacer=' | ', retain_newlines=True):
'''
"columns" is a list of tuples (width in chars, alignment) where
alignment is one of LEFT, CENTER or RIGHT.
"contents" is a list of chunks of text to format into each of the
columns.
'''
assert len(columns) == len(contents), \
'columns and contents must be same length'
self.columns = columns
self.num_columns = len(columns)
self.contents = contents
self.spacer = spacer
self.retain_newlines = retain_newlines
self.positions = [0]*self.num_columns
def format_line(self, wsre=re.compile(r'\s+')):
''' Fill up a single row with data from the contents.
'''
l = []
data = False
for i, (width, alignment) in enumerate(self.columns):
content = self.contents[i]
col = ''
while self.positions[i] < len(content):
word = content[self.positions[i]]
# if we hit a newline, honor it
if '\n' in word:
# chomp
self.positions[i] += 1
if self.retain_newlines:
break
word = word.strip()
# make sure this word fits
if col and len(word) + len(col) > width:
break
# no whitespace at start-of-line
if wsre.match(word) and not col:
# chomp
self.positions[i] += 1
continue
col += word
# chomp
self.positions[i] += 1
if col:
data = True
if alignment == CENTER:
col = '{:^{}}'.format(col.strip(), width)
elif alignment == RIGHT:
col = '{:>{}}'.format(col.rstrip(), width)
else:
col = '{:<{}}'.format(col.lstrip(), width)
l.append(col)
if data:
return self.spacer.join(l).rstrip()
# don't return a blank line
return ''
def format(self, splitre=re.compile(r'(\n|\r\n|\r|[ \t]|\S+)')):
# split the text into words, spaces/tabs and newlines
for i, content in enumerate(self.contents):
self.contents[i] = splitre.findall(content)
# now process line by line
l = []
line = self.format_line()
while line:
l.append(line)
line = self.format_line()
return '\n'.join(l)
def __str__(self):
return self.format()
def wrap(text, width=75, alignment=LEFT):
return FormatColumns(((width, alignment),), [text])
Diff to Previous Revision
--- revision 2 2011-02-20 23:59:07
+++ revision 3 2011-02-27 23:55:26
@@ -58,11 +58,11 @@
if col:
data = True
if alignment == CENTER:
- col = format(col.strip(), ' ^%s' % width)
+ col = '{:^{}}'.format(col.strip(), width)
elif alignment == RIGHT:
- col = format(col.rstrip(), ' >%s' % width)
+ col = '{:>{}}'.format(col.rstrip(), width)
else:
- col = format(col.lstrip(), ' <%s' % width)
+ col = '{:<{}}'.format(col.lstrip(), width)
l.append(col)
if data:
